DE filters and cartridge filters must be taken apart and cleaned as part of routine maintenance. DE filters once a year, and cartridge filters once every 6 months, or whenever the filter pressure goes up 10 pounds. Depending on the amount of dirt, debris or the bather load, etc, it may be necessary to clean a cartridge filter 3-4 times a year. You can backwash a DE filter, but residual build up of dirt, DE and debris, gets compacted between the grids and that can easily damage the grids. Opening the filter and cleaning and inspecting the grids must happen in addition to back washing throughout the year. Doing this maintenance can save you from unwanted problems and help save you money. Manifolds, air breather screens, cartridges and grids will last longer if they are kept clean and not allowed to get 'caked up' with debris.

If dirt and debris builds up too long and becomes compacted, it reduces water flow, basically acting like a cork. Floor heads may not 'pop up', or no longer have enough pressure to move dirt and debris toward the drain. Suction cleaners will not have the water flow required to move properly. Compacted dirt and debris can ruin cartridges prematurely and the weight of the residual DE in a DE filter, can cause the grids to collapse, breaking the skeletal plastic inside, or crack the manifold.

Anytime you have a filter apart, you should be inspecting the filter components for damage. Shown below, are some worst case scenarios. More than likely, if there are cracks, or tears to the degree shown in the images below, you may already have a green pool, or a dirty pool. Dirt and water would be bypassing the filter and blowing back into the pool. The idea of routine cleanings and inspections, is to discover potential problems early. What you will be looking for is hairline cracks in the manifold, or the cartridge filters rubber, or tiny tears in the DE filter grid material. If you see any kind of wear, or damage in the early stages, this is the time to replace the damaged parts before it becomes a bigger problem.

Look for a tear in the cartridge filters rubber. This started as a hairline crack and got worse over time.

Small tears in the DE filter grids, or broken plastic inside the grids are common when they get old, or have been neglected.

Cracks in the manifold like this one, can start as hairline cracks and get worse. It can also happen if you over tighten the nuts to the rods that hold the grids together. Always inspect the manifold for signs of stress.

This cartridge filters lower collection manifold had cracked and has holes in it. The filter went too long between cleanings. The cartridges were clogged, and the water had no where else to go.

This DE filters air breather screen has frayed and must be replaced. Once a hole has worn through the fabric, DE will get into the pool.